CA1186773A - Control system for a dual fuel internal combustion engine - Google Patents
Control system for a dual fuel internal combustion engineInfo
- Publication number
- CA1186773A CA1186773A CA000418186A CA418186A CA1186773A CA 1186773 A CA1186773 A CA 1186773A CA 000418186 A CA000418186 A CA 000418186A CA 418186 A CA418186 A CA 418186A CA 1186773 A CA1186773 A CA 1186773A
- Authority
- CA
- Canada
- Prior art keywords
- fuel
- valve
- engine
- metering
- control system
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D19/00—Controlling engines characterised by their use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures
- F02D19/06—Controlling engines characterised by their use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures peculiar to engines working with pluralities of fuels, e.g. alternatively with light and heavy fuel oil, other than engines indifferent to the fuel consumed
- F02D19/0639—Controlling engines characterised by their use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures peculiar to engines working with pluralities of fuels, e.g. alternatively with light and heavy fuel oil, other than engines indifferent to the fuel consumed characterised by the type of fuels
- F02D19/0642—Controlling engines characterised by their use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures peculiar to engines working with pluralities of fuels, e.g. alternatively with light and heavy fuel oil, other than engines indifferent to the fuel consumed characterised by the type of fuels at least one fuel being gaseous, the other fuels being gaseous or liquid at standard conditions
- F02D19/0647—Controlling engines characterised by their use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures peculiar to engines working with pluralities of fuels, e.g. alternatively with light and heavy fuel oil, other than engines indifferent to the fuel consumed characterised by the type of fuels at least one fuel being gaseous, the other fuels being gaseous or liquid at standard conditions the gaseous fuel being liquefied petroleum gas [LPG], liquefied natural gas [LNG], compressed natural gas [CNG] or dimethyl ether [DME]
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D19/00—Controlling engines characterised by their use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures
- F02D19/06—Controlling engines characterised by their use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures peculiar to engines working with pluralities of fuels, e.g. alternatively with light and heavy fuel oil, other than engines indifferent to the fuel consumed
- F02D19/0602—Control of components of the fuel supply system
- F02D19/0607—Control of components of the fuel supply system to adjust the fuel mass or volume flow
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D19/00—Controlling engines characterised by their use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures
- F02D19/06—Controlling engines characterised by their use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures peculiar to engines working with pluralities of fuels, e.g. alternatively with light and heavy fuel oil, other than engines indifferent to the fuel consumed
- F02D19/08—Controlling engines characterised by their use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures peculiar to engines working with pluralities of fuels, e.g. alternatively with light and heavy fuel oil, other than engines indifferent to the fuel consumed simultaneously using pluralities of fuels
- F02D19/081—Adjusting the fuel composition or mixing ratio; Transitioning from one fuel to the other
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T10/00—Road transport of goods or passengers
- Y02T10/10—Internal combustion engine [ICE] based vehicles
- Y02T10/30—Use of alternative fuels, e.g. biofuels
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Output Control And Ontrol Of Special Type Engine (AREA)
- Fuel-Injection Apparatus (AREA)
- Electrical Control Of Air Or Fuel Supplied To Internal-Combustion Engine (AREA)
Abstract
CONTROL SYSTEM FOR A DUAL FUEL INTERNAL
COMBUSTION ENGINE
Abstract of the Disclosure A control system is provided for regulating the fuel feed to a dual fuel internal combustion engine. The engine includes a source of first fuel, a pump therefor, and a source of second fuel under a predetermined pressure. A
first valve is mounted within a first feed line connecting the engine to the pump outlet. A second valve is mounted within a second feed line connecting the engine to the pump outlet. A third valve is mounted within a third feed line connecting the engine to the second fuel source. A pressure-sensitive metering valve is disposed within the third feed line downstream of the third valve. A means is provided which transmits the flow pressure from the second valve to the metering valve and thus, determines the setting of the latter. A control means, adjustable between two modes, is operatively connected to the first, second, and third valves.
When the control means is in a first mode, the first valve is open and both the second and third valves are closed whereby only the first fuel is fed to the engine. When the control means is in a second mode, the first valve is closed and both the second and third valves are open whereby both the first and second fuels are simultaneously fed to the engine. The ratio of the second fuel to the first fuel being fed to the engine, when the control means is in the second mode, is determined by the setting of the meter ing valve when said control means is in said second mode.
COMBUSTION ENGINE
Abstract of the Disclosure A control system is provided for regulating the fuel feed to a dual fuel internal combustion engine. The engine includes a source of first fuel, a pump therefor, and a source of second fuel under a predetermined pressure. A
first valve is mounted within a first feed line connecting the engine to the pump outlet. A second valve is mounted within a second feed line connecting the engine to the pump outlet. A third valve is mounted within a third feed line connecting the engine to the second fuel source. A pressure-sensitive metering valve is disposed within the third feed line downstream of the third valve. A means is provided which transmits the flow pressure from the second valve to the metering valve and thus, determines the setting of the latter. A control means, adjustable between two modes, is operatively connected to the first, second, and third valves.
When the control means is in a first mode, the first valve is open and both the second and third valves are closed whereby only the first fuel is fed to the engine. When the control means is in a second mode, the first valve is closed and both the second and third valves are open whereby both the first and second fuels are simultaneously fed to the engine. The ratio of the second fuel to the first fuel being fed to the engine, when the control means is in the second mode, is determined by the setting of the meter ing valve when said control means is in said second mode.
Description
7t~3 CONTROL SYSTEM FQR A DUAL FUEL INTE~NAL
COMBUSTION ENGINE
Because of the uncertainty in various geogxaphical regions throughout the world as to the supply and cost of liquid hydrocarbon fuel~ the dependence of these regions on such fuel as the SQ~ e fuel for internal combustion engines and the like, has adversely affected the economic stability and industrial development of such regionsO On the other hand, certain of these regions ha~e ready access to an in expensive source of natural gas (CNG~ and/or to a source of liquified petroleum gas (LPG) and thus r to utilize these sources to supplement the liquid hydrocarbon fuel would significantly improve the stabllity and d~velopment of lS these regionsO
Various systems have hexetofore been proposed t particularly with regard to diesel engines, in an efort to effectively supplement the fuel oil with a gaseous fuelO
Such s~stems, however, have baen beset with one or more of t~ following shor~comings: a) the system is of a costly/
bulky and complex construc ion; b) th installation of the system requires substantial modification of the engine design; c) the system is prone to malfunction; d) the system is effective only within a narrow operating range o the engine; e~ t:he system requires an inord.inate amount of service and maintenance, f) the savings in fuel oil C05tS
,~
'7~
:is only nominal; and g) the sys-tem adversely aEFects -the responses of the engine to various power demands.
~ of the Invention The invention provides a control system for a dual fuel in-ternal combustion engine, the latter having a firs-t fuel source and a second fuel source uncLer a prede-terminecL pressure, said sys-tem comprising: primary means for rnetering Euel to the engine Erom the firs-t Euel source as a function of engine load and operator demand; means for genera-ting a control signal as a func-tion of engine load; means for metering Euel from the second fuel source -to the engine as a Eunction oE said control signal whenever i-t is desired to operate the engine in a dual fuel mode; and means responsive to operation of the engine in a dual fuel mode for modulating the fuel metered by said primary meter-ing means by an amount which provides substantially the same fuel energy content delivered to the engine in the dual fuel mode as in the single -Euel mode; said primary fuel metering means including a variable speed fuel pump, and a first feed line for connecting said pump to the engine, and said modulating means including means disposed in said first feecd line for restricting flow a predetermined amount only when 'che engine is operating in the duel feed mode.
The improved control system for a dual fuel internal combustion engine disclosed herein avoids the aforenoted short-comings associated with prior systems of this type, and may be utilized effectively with internal combustion engines which vary in size and horsepower rating over a wide range. The fuel source for the engine can be readily switched Erom a single source to dual sources without requiring shutdown of the engine, and the proportion of the secondary or supplementary Euel supplied to the engine will be substantially consistent over the opera-ting range of -the engine.
In accordance with one embodiment of -the improved sys-tem a first valve is provided which is connected -to -the out--]et of a variable speed first fuel pump. The first valve is disposed within a first Eeed line connectinc1 the eny:ine -to the outlet of the fuel pump. A second feed line is also provided which connec-ts -the fuel pump outle-t -to the eng:ine.
- 2a -, . .
~ 3 --A second valve is disposed within the second feed line. The first fuel flows through the second valve and the second feed line only when the first valve is closed. A third valve is provided which is disposed within a third feed line con-necting the engine to a pressurized source o a second fuelnAlso disposed within the third feed line and downstream of -the third valve is a pressure-responsive me~ering valve.
The flow pressure of the firs~ fuel through the second valve i5 transmit~ed ~o the metering valve and the setting of the latter is dependent upon the transmitted flow pressure. Thus, the ratio of the second fuel flow to the first fuel flow is determined by the setting of the metering valve. An adjustable control is provided which is operatively connected to the first, second, and third valves and when in one position of adjustment causes the first valve to open and the second and third valves to be closed, whereby the engine operates with only one of the two fuels available. When the control is in a second position of adjustment, the first valve is closed and the second and third valves are opened resulting in the engine operating on a mixtuxe of both fuels.
Description For a more complete understand:ing of the invention, reference should be made to the drawing whereino ~ ig. 1 is a schematic view of one embodiment of the impxoved control system.
Fig. 2 is an enlarged fragmentary vertical sectional view of one form of a pressure responsive metering valv~
utilized in the system of FigO lo Referring now to the drawing and more particularly to Fig. 1, one form of the improved control system 10 is ~6773 shown which is adapted for use on an internal combustion engine E having dual fuel souxces Sl, S2. For purposes of fac.ilitating understanding the improved system~ the latter will be described with reference to a diesel powered engine u-tilizing a liquid hydrocarbon and compressed natural gas (CN~) as the available fuel sources Sl, S~
The liquid hydrocarbon (oil) is stoxed in conven-tional tank Sl having an exposed fill port F provided at the top of ~he tank and normally clo~ed by a screw-type cap C.
The natural gas supply may be provided xom a pressurized cyl~.nder of conventional design. The capacity of the cylinder may vary according to the size and rating of the engine and the anticipated power demands of the engine. The cylinder is preferred to be of a type which is readily capable of being recharged when required.
Extending rom the oil supply tank Sl is a flow line 11 which supplies oil to the input side of a conventional variable speed pump 12. It is customary for a fil~er 13 to be disposed within the line 11. Connected to the output side of pump 12 is a T~connector 14 having two outle~sO To one of ~he outlets i5 connected a first valve 15 which i5 preferably solenoid actuated. The outlet side of valve 15 is connected to one end of a first Euel line or rail 16.
The opposite end of fuel line 16 is connec~ed to the fuel intake manifold or directly to the various fuel injectors ut:ilized in khe engine~
The second outlet of the T-connector 14 is connected to a section 17a of a bypass fuel line 17~ The line ~ection 17a connect-s with a second solenoid actuated valve 18. Valve 18 has an outlet orifice of reduced size connected to a second secti.on 17b oE the bypass fuel line 17. In the illustrated embodiment line section ~7b is shown joining ~he feedline 16 at some point between valve 15 and the engine. If desired, however, line section 17b may be con-nected directly to the engine's fuel intake maniEold.
Leading rom valve 18 or from line sec~ion 17a is a fuel pressure line 20, the unction of whlch will be described more fully hereinafter. Fuel from pump 12 will Elow through valve 18 only when valve 15 assumes a closed position and valve 18 assumes its open pos:ition.
The source of compressed natu~al gas S2, which is stored in a suitable pressurized cylinder, flows rom the latter to the air intake manifold of the engine E through a suitable feedline 21. ~he line 21 may be flexible and is required to be strong enough to withstand substantial internal gas pressures (e.g~ 100 psi)o Disposed within feedline 21 is a third solenoid actuated valve 22. The valve 22 is a safety valve and normally remai~s closed except when both types of fuel are to be simultaneously fed to the engineO A conventional regulator 23 may be disposed within line 21 downstream from the third valve 22~ Regulator 23 serves to reduce tank pressure to a level suitable for meteringO
Downstream of regulator 23 and disposed within l.ine 21 is a metering valve 24, the setting of which is responsive ~o the flow or rail pressure of the fuel maintained within line 20. The pressure maintained in line 20 is directly re:Lated to the load demands imposed on the engine E; such demands in turn are directly reflec~ed by the impeller speed of the p~npc The responsiveness of the metering valve 24 to the variations in rail pressuxe is effected through a hydraulic piston-cyli~der assembly 25. One end of the assembly cylinder 26~ see Fig. 2, is provided with a port 26a to which is 7~
connected an end 20a of line 20. Slidably disposed within -the cylinder 26 is a pis~on 27. The side o~ the piston 27 opposite port 26a is provided with a spring 36 to bias the piston 27 against the pressure from port 26a. Projecting e~ternally from an end of the cylinder 26 ls a rod 28 which is attached to one side of piston 27. The exposed end of the rod 28 is threadably attached to a suitable connector 30 and the rod side of piston 27 may be ~ented to the atmosphere~
Connector 30 is at one end of an arm 30a, pivotally mounted at 30b, which has the other end 30c pivo~ally con-nected to a valve stem 31. The opposite end of the valve stem 31 is secured to and operates a suitable metering valve 24 .in such a manner that the valve opening is a direct function of the movement of the valve stem 31.
While adjustment of the metering valve 24 in the illustrated embodiment i5 produced by the hydraulic piston-cylinder assembly 25, other means for obtaining such adjust-ment can be utilized for example, the valve piece could be operatively connected to the thro~tle lever, or the fuel rack Qf the engine or to some electronic sensing means embodied in the engine.
The extent to which the metering valve 24 i5 opened is dependent upon the movement of piston 27 within the cylinder 26. By adjusting the threaded connector 30 on the rod 28, the bias exerted on the piston 27 by spring 36 to.retain the metering valve 24 in a closed position can be predetermined. Thus, the responsiveness of the metering valve 24 to the rail or fuel pressure with.in l.ine 20 can be carefully controlled thereby controlling the ratio of the gas fuel to the liquid fuel being supplied to the ~ngine when the switch is adjusted ~o a particular mode. Thus, i7~
the ratio of the dual fuels supplied -to the engine will be con~isten-t with the power demands imposed on the enyine.
The mode in which t]he engine is operat:ing- that is to say, whether it is fed only a single fuel or a mixture of two uels-~depends upon ~o which of two posi-tions the elec-trical switch 37 is adjusted~ Switch 37 has an adjustable lever 37a connected to a power source no~ showrl, and two terminals 37b, 37c connected respectivel~ ko the solenoid actua~ing valve 15 and the solenoids actuating valves 18 and 22. Valve Z2, when de-enexgized, normally assumes a closed position, thus shutting off flow of the compressed gas fuel rom source S2 through line 21 to the engine Eo Also, when valve 18 is not energized--tha~ is, when the switch lever 37a is out of contact with terminal 37c--the valve 18 will ~S assume a closed position and prevent flow of the liquid fuel through line 17 to the engine. When lever 37a is out of contact with terminal 37b, valve 15 will assume a closed position whereby the liquid fuel flow will be diverted through valve 18~ Switch 37 is preferably a two position type and may be actuated when the engine is operating.
While the contxol for actuating the valves 15, 18, and 22 has been described as an electrical swi~ch~ it may instead be a pneumatic, hydraulic, or mechanical device which would cause adjustment of the valves~
The ~ystem as herein described utiliæes two fuels, one of which is a liquid and the other compressed natural gas; however, it is not intended to be so limitedO
Anothex secondary source of fuel may be liquified petroleum gas (LPG~
When the engin2 E is started up with switch 37 in the mode wherein lever 37a is in contact with terminal 37c, piston 27 wlll be moved by the pressuxe in line 20 causing the valve 22 to op~n. ~hen this occurs, the gaseous fuel ;773 from source S2 will flow into line 21 leading to the air intake of the engine. During this time period, liquid fuel from Sl is passing rom pump L2 through valve 18 into feed line 17 and then to the injectors o the engine E. Upon the liquid fuel being injected in a timed sequence into the cylinders of the engine, it will igni~e b~ reason o~ the high compression developed within the cylinders. The gas fuel simultaneously introduced into the cylinders will be ignited by the ignited liquid uel. In such a sequence of events the injected liquid fuel functions as the ignition means for the second fuel.
As aforementioned, the ratio of the first fuel to the second uel being fed to the engine can be varied as desired through adjusting various components of the metering valve 24 as previously described. It has be~n found, for example, in a Cummins V8 210 h.p. engine, presently available on the market and manufac~ured by Cummins Engine Company, Inc.
of Columbus, ~ndiana, that a liquid fuel to gaseous fuel ratio of 3 to 1 results in favorable operation of the engine~ Other ratios wherein there is a grea~er proportion of the gaseous fuel are contemplated and will depend upon the size and type of engine and on the cost and availability of the fuels being utilized.
Thus, it will be noted that a control system for a duaL fuel internal combustion engine has been disclosed which utilizes a simple and efficient fuel feed means wherein a compression ignition (diesel) engine can be readily modified to.burn a pxedetermined proportion of a gaseous fuel as a source of power for the engine. Furthermore, the improved system has been provided whexein the ratio of the dual fuels supplied to the engine will be substantially consistent over the opera'cing range of the engine and significant savings in liquid fllel co~ts will result.
I claim:
COMBUSTION ENGINE
Because of the uncertainty in various geogxaphical regions throughout the world as to the supply and cost of liquid hydrocarbon fuel~ the dependence of these regions on such fuel as the SQ~ e fuel for internal combustion engines and the like, has adversely affected the economic stability and industrial development of such regionsO On the other hand, certain of these regions ha~e ready access to an in expensive source of natural gas (CNG~ and/or to a source of liquified petroleum gas (LPG) and thus r to utilize these sources to supplement the liquid hydrocarbon fuel would significantly improve the stabllity and d~velopment of lS these regionsO
Various systems have hexetofore been proposed t particularly with regard to diesel engines, in an efort to effectively supplement the fuel oil with a gaseous fuelO
Such s~stems, however, have baen beset with one or more of t~ following shor~comings: a) the system is of a costly/
bulky and complex construc ion; b) th installation of the system requires substantial modification of the engine design; c) the system is prone to malfunction; d) the system is effective only within a narrow operating range o the engine; e~ t:he system requires an inord.inate amount of service and maintenance, f) the savings in fuel oil C05tS
,~
'7~
:is only nominal; and g) the sys-tem adversely aEFects -the responses of the engine to various power demands.
~ of the Invention The invention provides a control system for a dual fuel in-ternal combustion engine, the latter having a firs-t fuel source and a second fuel source uncLer a prede-terminecL pressure, said sys-tem comprising: primary means for rnetering Euel to the engine Erom the firs-t Euel source as a function of engine load and operator demand; means for genera-ting a control signal as a func-tion of engine load; means for metering Euel from the second fuel source -to the engine as a Eunction oE said control signal whenever i-t is desired to operate the engine in a dual fuel mode; and means responsive to operation of the engine in a dual fuel mode for modulating the fuel metered by said primary meter-ing means by an amount which provides substantially the same fuel energy content delivered to the engine in the dual fuel mode as in the single -Euel mode; said primary fuel metering means including a variable speed fuel pump, and a first feed line for connecting said pump to the engine, and said modulating means including means disposed in said first feecd line for restricting flow a predetermined amount only when 'che engine is operating in the duel feed mode.
The improved control system for a dual fuel internal combustion engine disclosed herein avoids the aforenoted short-comings associated with prior systems of this type, and may be utilized effectively with internal combustion engines which vary in size and horsepower rating over a wide range. The fuel source for the engine can be readily switched Erom a single source to dual sources without requiring shutdown of the engine, and the proportion of the secondary or supplementary Euel supplied to the engine will be substantially consistent over the opera-ting range of -the engine.
In accordance with one embodiment of -the improved sys-tem a first valve is provided which is connected -to -the out--]et of a variable speed first fuel pump. The first valve is disposed within a first Eeed line connectinc1 the eny:ine -to the outlet of the fuel pump. A second feed line is also provided which connec-ts -the fuel pump outle-t -to the eng:ine.
- 2a -, . .
~ 3 --A second valve is disposed within the second feed line. The first fuel flows through the second valve and the second feed line only when the first valve is closed. A third valve is provided which is disposed within a third feed line con-necting the engine to a pressurized source o a second fuelnAlso disposed within the third feed line and downstream of -the third valve is a pressure-responsive me~ering valve.
The flow pressure of the firs~ fuel through the second valve i5 transmit~ed ~o the metering valve and the setting of the latter is dependent upon the transmitted flow pressure. Thus, the ratio of the second fuel flow to the first fuel flow is determined by the setting of the metering valve. An adjustable control is provided which is operatively connected to the first, second, and third valves and when in one position of adjustment causes the first valve to open and the second and third valves to be closed, whereby the engine operates with only one of the two fuels available. When the control is in a second position of adjustment, the first valve is closed and the second and third valves are opened resulting in the engine operating on a mixtuxe of both fuels.
Description For a more complete understand:ing of the invention, reference should be made to the drawing whereino ~ ig. 1 is a schematic view of one embodiment of the impxoved control system.
Fig. 2 is an enlarged fragmentary vertical sectional view of one form of a pressure responsive metering valv~
utilized in the system of FigO lo Referring now to the drawing and more particularly to Fig. 1, one form of the improved control system 10 is ~6773 shown which is adapted for use on an internal combustion engine E having dual fuel souxces Sl, S2. For purposes of fac.ilitating understanding the improved system~ the latter will be described with reference to a diesel powered engine u-tilizing a liquid hydrocarbon and compressed natural gas (CN~) as the available fuel sources Sl, S~
The liquid hydrocarbon (oil) is stoxed in conven-tional tank Sl having an exposed fill port F provided at the top of ~he tank and normally clo~ed by a screw-type cap C.
The natural gas supply may be provided xom a pressurized cyl~.nder of conventional design. The capacity of the cylinder may vary according to the size and rating of the engine and the anticipated power demands of the engine. The cylinder is preferred to be of a type which is readily capable of being recharged when required.
Extending rom the oil supply tank Sl is a flow line 11 which supplies oil to the input side of a conventional variable speed pump 12. It is customary for a fil~er 13 to be disposed within the line 11. Connected to the output side of pump 12 is a T~connector 14 having two outle~sO To one of ~he outlets i5 connected a first valve 15 which i5 preferably solenoid actuated. The outlet side of valve 15 is connected to one end of a first Euel line or rail 16.
The opposite end of fuel line 16 is connec~ed to the fuel intake manifold or directly to the various fuel injectors ut:ilized in khe engine~
The second outlet of the T-connector 14 is connected to a section 17a of a bypass fuel line 17~ The line ~ection 17a connect-s with a second solenoid actuated valve 18. Valve 18 has an outlet orifice of reduced size connected to a second secti.on 17b oE the bypass fuel line 17. In the illustrated embodiment line section ~7b is shown joining ~he feedline 16 at some point between valve 15 and the engine. If desired, however, line section 17b may be con-nected directly to the engine's fuel intake maniEold.
Leading rom valve 18 or from line sec~ion 17a is a fuel pressure line 20, the unction of whlch will be described more fully hereinafter. Fuel from pump 12 will Elow through valve 18 only when valve 15 assumes a closed position and valve 18 assumes its open pos:ition.
The source of compressed natu~al gas S2, which is stored in a suitable pressurized cylinder, flows rom the latter to the air intake manifold of the engine E through a suitable feedline 21. ~he line 21 may be flexible and is required to be strong enough to withstand substantial internal gas pressures (e.g~ 100 psi)o Disposed within feedline 21 is a third solenoid actuated valve 22. The valve 22 is a safety valve and normally remai~s closed except when both types of fuel are to be simultaneously fed to the engineO A conventional regulator 23 may be disposed within line 21 downstream from the third valve 22~ Regulator 23 serves to reduce tank pressure to a level suitable for meteringO
Downstream of regulator 23 and disposed within l.ine 21 is a metering valve 24, the setting of which is responsive ~o the flow or rail pressure of the fuel maintained within line 20. The pressure maintained in line 20 is directly re:Lated to the load demands imposed on the engine E; such demands in turn are directly reflec~ed by the impeller speed of the p~npc The responsiveness of the metering valve 24 to the variations in rail pressuxe is effected through a hydraulic piston-cyli~der assembly 25. One end of the assembly cylinder 26~ see Fig. 2, is provided with a port 26a to which is 7~
connected an end 20a of line 20. Slidably disposed within -the cylinder 26 is a pis~on 27. The side o~ the piston 27 opposite port 26a is provided with a spring 36 to bias the piston 27 against the pressure from port 26a. Projecting e~ternally from an end of the cylinder 26 ls a rod 28 which is attached to one side of piston 27. The exposed end of the rod 28 is threadably attached to a suitable connector 30 and the rod side of piston 27 may be ~ented to the atmosphere~
Connector 30 is at one end of an arm 30a, pivotally mounted at 30b, which has the other end 30c pivo~ally con-nected to a valve stem 31. The opposite end of the valve stem 31 is secured to and operates a suitable metering valve 24 .in such a manner that the valve opening is a direct function of the movement of the valve stem 31.
While adjustment of the metering valve 24 in the illustrated embodiment i5 produced by the hydraulic piston-cylinder assembly 25, other means for obtaining such adjust-ment can be utilized for example, the valve piece could be operatively connected to the thro~tle lever, or the fuel rack Qf the engine or to some electronic sensing means embodied in the engine.
The extent to which the metering valve 24 i5 opened is dependent upon the movement of piston 27 within the cylinder 26. By adjusting the threaded connector 30 on the rod 28, the bias exerted on the piston 27 by spring 36 to.retain the metering valve 24 in a closed position can be predetermined. Thus, the responsiveness of the metering valve 24 to the rail or fuel pressure with.in l.ine 20 can be carefully controlled thereby controlling the ratio of the gas fuel to the liquid fuel being supplied to the ~ngine when the switch is adjusted ~o a particular mode. Thus, i7~
the ratio of the dual fuels supplied -to the engine will be con~isten-t with the power demands imposed on the enyine.
The mode in which t]he engine is operat:ing- that is to say, whether it is fed only a single fuel or a mixture of two uels-~depends upon ~o which of two posi-tions the elec-trical switch 37 is adjusted~ Switch 37 has an adjustable lever 37a connected to a power source no~ showrl, and two terminals 37b, 37c connected respectivel~ ko the solenoid actua~ing valve 15 and the solenoids actuating valves 18 and 22. Valve Z2, when de-enexgized, normally assumes a closed position, thus shutting off flow of the compressed gas fuel rom source S2 through line 21 to the engine Eo Also, when valve 18 is not energized--tha~ is, when the switch lever 37a is out of contact with terminal 37c--the valve 18 will ~S assume a closed position and prevent flow of the liquid fuel through line 17 to the engine. When lever 37a is out of contact with terminal 37b, valve 15 will assume a closed position whereby the liquid fuel flow will be diverted through valve 18~ Switch 37 is preferably a two position type and may be actuated when the engine is operating.
While the contxol for actuating the valves 15, 18, and 22 has been described as an electrical swi~ch~ it may instead be a pneumatic, hydraulic, or mechanical device which would cause adjustment of the valves~
The ~ystem as herein described utiliæes two fuels, one of which is a liquid and the other compressed natural gas; however, it is not intended to be so limitedO
Anothex secondary source of fuel may be liquified petroleum gas (LPG~
When the engin2 E is started up with switch 37 in the mode wherein lever 37a is in contact with terminal 37c, piston 27 wlll be moved by the pressuxe in line 20 causing the valve 22 to op~n. ~hen this occurs, the gaseous fuel ;773 from source S2 will flow into line 21 leading to the air intake of the engine. During this time period, liquid fuel from Sl is passing rom pump L2 through valve 18 into feed line 17 and then to the injectors o the engine E. Upon the liquid fuel being injected in a timed sequence into the cylinders of the engine, it will igni~e b~ reason o~ the high compression developed within the cylinders. The gas fuel simultaneously introduced into the cylinders will be ignited by the ignited liquid uel. In such a sequence of events the injected liquid fuel functions as the ignition means for the second fuel.
As aforementioned, the ratio of the first fuel to the second uel being fed to the engine can be varied as desired through adjusting various components of the metering valve 24 as previously described. It has be~n found, for example, in a Cummins V8 210 h.p. engine, presently available on the market and manufac~ured by Cummins Engine Company, Inc.
of Columbus, ~ndiana, that a liquid fuel to gaseous fuel ratio of 3 to 1 results in favorable operation of the engine~ Other ratios wherein there is a grea~er proportion of the gaseous fuel are contemplated and will depend upon the size and type of engine and on the cost and availability of the fuels being utilized.
Thus, it will be noted that a control system for a duaL fuel internal combustion engine has been disclosed which utilizes a simple and efficient fuel feed means wherein a compression ignition (diesel) engine can be readily modified to.burn a pxedetermined proportion of a gaseous fuel as a source of power for the engine. Furthermore, the improved system has been provided whexein the ratio of the dual fuels supplied to the engine will be substantially consistent over the opera'cing range of the engine and significant savings in liquid fllel co~ts will result.
I claim:
Claims (11)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A control system for a dual fuel internal combustion engine, the latter having a first fuel source and a second fuel.
source under a predetermined pressure, said system comprising:
primary means for metering fuel to the engine from the first fuel source as a function of engine load and operator demand;
means for generating a control signal as a function of engine load; means for metering fuel from the second fuel source to the engine as a function of said control signal whenever it is desired to operate the engine in a dual fuel mode; and means responsive to operation of the engine in a dual fuel mode for modulating the fuel metered by said primary metering means by an amount which provides substantially the same fuel energy content delivered to the engine in the dual fuel mode as in the single fuel mode; said primary fuel metering means including a variable speed fuel pump, and a first feed line for connecting said pump to the engine, and said modulating means including means disposed in said first feed line for restricting flow a predetermined amount only when the engine is operating in the dual feed mode.
source under a predetermined pressure, said system comprising:
primary means for metering fuel to the engine from the first fuel source as a function of engine load and operator demand;
means for generating a control signal as a function of engine load; means for metering fuel from the second fuel source to the engine as a function of said control signal whenever it is desired to operate the engine in a dual fuel mode; and means responsive to operation of the engine in a dual fuel mode for modulating the fuel metered by said primary metering means by an amount which provides substantially the same fuel energy content delivered to the engine in the dual fuel mode as in the single fuel mode; said primary fuel metering means including a variable speed fuel pump, and a first feed line for connecting said pump to the engine, and said modulating means including means disposed in said first feed line for restricting flow a predetermined amount only when the engine is operating in the dual feed mode.
2. The control system of claim 1 wherein said flow restricting means comprises a first valve disposed in said first feed line, and a second feed line and second valve means having a predetermined restriction connected to said first feed line and in parallel flow relation to said first valve, and control means adjustable between two modes and operatively connected to said first and second valves and said second fuel source meter-ing means, when in a first mode said control means effecting opening of said first valve and closing said second valve means and termination of metering by said second fuel source metering means during the single fuel mode and when in a second mode said control means effecting closing of said first valve and opening of said second valve means and metering by said second fuel source metering means during the dual fuel mode.
3. The control system of claim 1, wherein said second fuel source metering means comprises a third feed line for con-necting the second fuel source to the engine, a third valve disposed in said third feed line, and a metering valve disposed in said third fuel line in series flow relation to said third valve, the flow area of said metering valve being a function of said control signal and wherein said third valve is operatively connected to said control means to be opened and closed in synchronism with said second valve.
4. The control system of claim 3 wherein the first, second, and third valves are electrically energized solenoid valves.
5. The control system of claim 4 wherein the control means is a manually actuated two position electrical switch.
6. The control system of claim 1 wherein the first fuel is a liquid hydrocarbon.
7. The control system of claim 1 wherein said second fuel source metering means comprises: means for selectively permit-ting or blocking flow of fuel from second fuel source to the engine, a variable area metering valve for metering fuel from the second fuel source to the engine as a function of a displace-ment input, and an actuator operatively connected to said meter-ing valve and being responsive to said signal for increasing the area thereof as the signal increases.
8. The control system of claim 7 wherein said control signal is in fluid pressure form, said actuator comprises a cylinder and piston displaceable therein, a spring urging the piston in a first direction, said control signal being connected to said cylinder in opposition to said spring to producing a predetermined displacement of the piston in response to increase in signal pressure, and a mechanical linkage of connecting the piston to said metering valve so that an increase in signal pressure increases the opening of said metering valve.
9. The control system of claim 8 wherein said mechanical linkage has an adjustable link for adjusting the response of said piston to variations in signal pressure.
10. The control system of claim 7 wherein said actuator is responsive to a fluid pressure signal, said fuel pump produces an output fuel pressure that is a direct function of engine load, and said control signal generating means comprises a means for connecting the output of said fuel pump to said metering valve means, the metering valve means metering an increasing amount of fuel from the second source in response to an increase in the control signal.
11. A control system as in claim 8 wherein said fuel pump produces an output fuel pressure that is a direct function of engine load and said control signal generating means comprises a means for connecting the output of said fuel pump to the cylin-der.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US06/334,374 US4416244A (en) | 1981-12-24 | 1981-12-24 | Control system for a dual fuel internal combustion engine |
| US334,374 | 1981-12-24 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1186773A true CA1186773A (en) | 1985-05-07 |
Family
ID=23306915
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000418186A Expired CA1186773A (en) | 1981-12-24 | 1982-12-21 | Control system for a dual fuel internal combustion engine |
Country Status (9)
| Country | Link |
|---|---|
| US (1) | US4416244A (en) |
| AU (1) | AU550833B2 (en) |
| BR (1) | BR8207386A (en) |
| CA (1) | CA1186773A (en) |
| GB (1) | GB2112457B (en) |
| IN (1) | IN161017B (en) |
| IT (1) | IT1153881B (en) |
| MX (1) | MX157204A (en) |
| NZ (1) | NZ202858A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2007104148A1 (en) * | 2006-03-10 | 2007-09-20 | Westport Power Inc. | Method and apparatus for operating a dual fuel internal combustion engine |
Families Citing this family (24)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA1226183A (en) * | 1982-10-30 | 1987-09-01 | Timothy J. Bedford | Fuel oil injection engine |
| NZ205140A (en) * | 1983-08-04 | 1987-02-20 | H M Reid | Electronically controlled dual fuel system for diesel engines |
| US4535728A (en) * | 1984-02-02 | 1985-08-20 | Propane Carburetion Systems, Inc. | Fuel feed control system and control valve for dual fuel operation of an internal combustion engine |
| US4637353A (en) * | 1984-02-06 | 1987-01-20 | Codrington Ernest R | Pilot fuel regulating device |
| US4597364A (en) * | 1984-04-30 | 1986-07-01 | Emco Wheaton International Limited | Fuel control system for gaseous fueled engines |
| GB8425577D0 (en) * | 1984-10-10 | 1984-11-14 | Flintheath Ltd | Fuel control system |
| US4708094A (en) * | 1986-12-15 | 1987-11-24 | Cooper Industries | Fuel control system for dual fuel engines |
| US5775309A (en) * | 1997-07-14 | 1998-07-07 | Impco Technologies, Inc. | Pre-adjustable fueling system for dual fuel engine |
| US6276345B1 (en) | 1998-12-23 | 2001-08-21 | Kohler Co. | Dual fuel system for an internal combustion engine |
| NL1011844C2 (en) * | 1999-04-20 | 2000-10-23 | Petrocare B V | Method and system for preparing an air-fuel mixture. |
| DE60220456T2 (en) * | 2001-04-09 | 2008-01-24 | Turner, Geoffrey Russell | Fuel supply system |
| US7506638B2 (en) | 2001-04-09 | 2009-03-24 | Geoffrey Russell Turner | Fuel delivery system |
| US6863034B2 (en) * | 2003-01-17 | 2005-03-08 | Robert D. Kern | Method of controlling a bi-fuel generator set |
| US7591253B2 (en) * | 2006-07-28 | 2009-09-22 | Proinjects, L.L.C. | Secondary fuel system for diesel engines |
| WO2011129835A1 (en) * | 2010-04-16 | 2011-10-20 | Gometal Llc | A replacement kit for installing a compressed natural gas (cng)/fuel dual system for motorcycles |
| US9115653B2 (en) * | 2012-03-27 | 2015-08-25 | Ford Global Technologies, Llc | System and method for emptying a tank |
| US9212643B2 (en) * | 2013-03-04 | 2015-12-15 | Delia Ltd. | Dual fuel system for an internal combustion engine |
| US9435273B2 (en) | 2013-11-01 | 2016-09-06 | Champion Engine Technology, LLC | Dual fuel selector switch |
| US9410490B2 (en) | 2014-02-06 | 2016-08-09 | Cummins, Inc. | Fuel selection system and method for dual fuel engines |
| CN106460730B (en) * | 2014-05-30 | 2019-07-02 | 瓦锡兰芬兰有限公司 | The method of the box-type container of the fuel tank apparatus and operating ship of ship |
| WO2016073588A1 (en) | 2014-11-04 | 2016-05-12 | Cummins Inc. | Systems, methods, and apparatus for operation of dual fuel engines |
| US10221780B2 (en) | 2015-06-12 | 2019-03-05 | Champion Power Equipment, Inc. | Dual fuel lockout switch for generator engine |
| US10697398B2 (en) | 2015-06-12 | 2020-06-30 | Champion Power Equipment, Inc. | Batteryless dual fuel engine with liquid fuel cut-off |
| US10393034B2 (en) | 2015-06-12 | 2019-08-27 | Champion Power Equipment, Inc. | Fuel system for a multi-fuel internal combustion engine |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2793629A (en) * | 1955-12-02 | 1957-05-28 | California Research Corp | Internal combustion engine fuel systems |
| US2947291A (en) * | 1958-02-27 | 1960-08-02 | Continental Motors Corp | Compression ignition engine |
| US3308794A (en) * | 1964-12-21 | 1967-03-14 | Caterpillar Tractor Co | Engine fuel system |
| SU769054A1 (en) * | 1978-01-03 | 1980-10-07 | Рязанский сельскохозяйственный институт им.проф.П.А.Костычева | System for feeding two fuel into diesel |
| US4227497A (en) * | 1979-06-04 | 1980-10-14 | Mathieson Roy W | Fuel metering and transfer control system |
-
1981
- 1981-12-24 US US06/334,374 patent/US4416244A/en not_active Expired - Lifetime
-
1982
- 1982-11-16 MX MX195674A patent/MX157204A/en unknown
- 1982-12-10 GB GB08235252A patent/GB2112457B/en not_active Expired
- 1982-12-20 NZ NZ202858A patent/NZ202858A/en unknown
- 1982-12-20 BR BR8207386A patent/BR8207386A/en not_active IP Right Cessation
- 1982-12-21 CA CA000418186A patent/CA1186773A/en not_active Expired
- 1982-12-23 IT IT24957/82A patent/IT1153881B/en active
- 1982-12-23 AU AU91884/82A patent/AU550833B2/en not_active Expired
- 1982-12-24 IN IN1488/CAL/82A patent/IN161017B/en unknown
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2007104148A1 (en) * | 2006-03-10 | 2007-09-20 | Westport Power Inc. | Method and apparatus for operating a dual fuel internal combustion engine |
Also Published As
| Publication number | Publication date |
|---|---|
| GB2112457A (en) | 1983-07-20 |
| IN161017B (en) | 1987-09-12 |
| NZ202858A (en) | 1986-05-09 |
| US4416244A (en) | 1983-11-22 |
| AU9188482A (en) | 1983-06-30 |
| GB2112457B (en) | 1985-11-13 |
| IT8224957A0 (en) | 1982-12-23 |
| MX157204A (en) | 1988-11-03 |
| AU550833B2 (en) | 1986-04-10 |
| IT8224957A1 (en) | 1984-06-23 |
| IT1153881B (en) | 1987-01-21 |
| BR8207386A (en) | 1983-10-18 |
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